GRAPEVINE FLEA-BEETLES. 23 



Philadelphia vireo (Vireosylva philadelphica) , Carolina wren (Thry- 

 othorus ludovicianus) , and bluebird (Sialia sialis). 



METHODS OF CONTROL. 



As previously stated, no extensive infestation of either species of 

 flea-beetle came under the writer's observation in the Erie-Chautauqua 

 grape belt, and those infestations that did occur were confined to 

 vines at the ends of rows or the edges of vineyards. 1 In such situa- 

 tions hand-picking the beetles was the best means of control. The 

 effect of this method is immediate, which is very desirable against 

 so voracious an insect, against which arsenical sprays actcomparatively 

 slowly. On small areas in a corner or at the edge it is also cheaper 

 than the employment of a power sprayer, which must be drawn the 

 entire length of each row, of which only a small part may be infested. 

 Had an extensive infestation occurred, spraying would have been 

 resorted to, but as none was present no spraying experiments 

 were conducted. 



The application of a spray mixture containing 3 pounds of arsenate 

 of lead paste (H pounds, powdered) to 50 gallons of Bordeaux mix- 

 ture is usually recommended for the control of the typical species. 

 One of the recent investigators, Hartzell (££), states that this mixture 

 protects the vines from severe injury because it is repellent to the 

 beetles and disperses them over the vineyard, but that it does not kill 

 them. To kill the beetles he has found that a high dosage of arsenate 

 of lead, not less than 4 pounds paste (2 pounds, powdered) to 50 

 gallons of water, is most effective. This high dosage is necessary 

 to kill the beetles quickly before much damage is done, because of 

 their voracity and resistance to poison. He also states that the 

 effectiveness of the poison is much increased by the addition of 

 one-half gallon of molasses to the foregoing mixture. The addition 

 of molasses because of its solubility has the disadvantage, however, 

 of making the poison likely to be washed off by rains. Owing to the 

 frequency of rains at this season of the year this is a very serious 

 disadvantage. Molasses should not he added to a spray solution 

 containing Bordeaux -mixture, or hurning of the foliage is apt to 

 result. The time of application should be on the first warm day 

 when the grape buds are swelling, or as soon as the beetles appear. 



The difficulty of destroying the adults makes it important that 

 these pests be not allowed to reproduce in a vineyard. The 



1 After this paper had gone to press, in the spring of 1920, the writer's attention was called to extensive 

 destructiveness by A. chalybca at Neosho, Mo., by Mr. F. W. Faurot, director of the Missouri State Fruit 

 Experiment Station at Mountain Grove, Mo. It was stated that the greater part of the crop in a number 

 of vineyards had been destroyed by the activities of this beetle during the previous season. In 1920 it was 

 apparently much the most destructive grape insect of the region. Spraying experiments for the control 

 of beetles emerging from hibernation were conducted by Mr. A. J. Ackerman and the writer, in cooperation 

 with the Missouri Fruit Experiment Station. Arsenate of lead at the rate of 3 pounds (powdered) to 50 

 gallons of water gave fair control, and this dosage was much more effective than one of 2 pounds to 50 gallons 

 of water. 



